I've spent fifteen years running searches for founders, mostly in startup-adjacent spaces. The number one thing that wrecks early hires isn't comp, isn't the resume, isn't even the interview. It's that the founder got to the end of three rounds and said "I just feel like they fit."
Culture fit is what people say when they don't know what to assess.
What "fit" usually means in practice: I'd grab a beer with them.
The beer test will absolutely produce a homogeneous team that nods along until you have a problem no one wants to flag.
What I look for instead, and what I tell my clients to look for, is operating fit. Three questions.
How do they handle ambiguity. Most early-stage roles are 60% undefined work. Ask about the last time the goal moved on them mid-project and what they did. Specifics, not vibes.
How do they handle conflict. Not "what's a time you disagreed with someone." Everyone has a rehearsed answer. Ask: in the last 12 months, who did you push back on most, and what was the outcome. The flinch is the data.
How do they handle their own mistakes. Walk through the last thing they shipped that didn't work. If they have a clean story, they're either lying or they haven't shipped much.
None of those are "fit." They're behaviour. Behaviour is what you actually need to predict.
What's the hiring filter you wish you'd dropped earlier? Curious where other founders landed.